This policy brief aims to promote better management of aquaculture-based fisheries enhancements (stocking of hatchery fish to improve fisheries) through integrated analysis of enhancement systems and quantitative assessment of management practices through use of the EnhanceFish decision tool.

‘Spawn’ is the name for the young fish about three days old that are available from hatcheries. Sometimes these young fish are also called hatchlings. The spawn of catla, rohu and mrigal is about 6-8 mm long. At this stage, the ‘yolk sac’ is absorbed, the mouth opened and the fins fully developed. Spawn are reared intensively, first to the ‘fry’ size and then to the ‘fingerling’ size. All the three stages are marketed and collectively called ‘seed’.

The “fast fingerling system” can produce advanced fingerlings about two months earlier than they are normally available from fish farms.  The farmer uses just one pond for continuous growing until fingerling size is reached, and fewer fish are stocked. A farmer with a small, seasonal pond can produce fingerlings in one month. These can then be sold for a high price because everyone wants fingerlings as early as possible.

White tail disease in Macrobrachium rosenbergii is emerging as a serious problem in the region. Two viruses, M. rosenbergii nodavirus (MrNA) and extra small virus (XSV) have been found to be associated. The role of MrNV and XSV is not yet clear. Considering the economic impact and potential for the disease to spread, white tail disease (MrNV and XSV) has been listed under non-OIE listed crustacean diseases relevant to the region and NACA/FAO/OIE Regional QAAD list.

The fingerling rearing pond, like the nursery pond, should be free from weeds and predators. Submerged weeds and predators are killed by mahua oilcake, which then acts as a good fertiliser. If there are no weeds, to kill predators and competitors quickly you can just add 100 kg of urea followed 24 hours later by 200 kg of fresh bleaching powder for a 1-ha area of a 1-m deep pond.

This report provides insight into the status of the marine ornamental fish trade in the Philippines, including policy environment, collection, distribution channels, markets and constraints. The report also reviews the livelihoods of poor stakeholders in market chains including economic and financial aspects, natural and physical resources, livelihood patterns, social structures. The report provides recommendations for policy makers and stakeholders in improving the livelihoods of poor stakeholders in marine ornamental fish collection and market chains and resource management.

This is the proceedings of the workshop on Building capacity to combat impacts of aquatic invasive alien species and associated trans-boundary pathogens in ASEAN countries, held in Penang, Malaysia, on the 12th-16th July 2004. The workshop built on the recommendations from a 2002 workshop organised by the Global Invasive Species Program and a 2003 workshop of countries sharing the Mekong watershed, in promoting awareness, coordination mechanisms and information exchange systems and identifying management and risk mitigation measures.

In watersheds, medium irrigation projects can be useful for aquaculture even though these water bodies are many times larger than ponds, and are basically built for irrigation or water storage. However, the full potential of these water bodies is not yet realised. Net pens or cages can be used to rear fingerlings in such environments.

It is best to stock advanced fingerlings in large ponds, tanks, and in both small and large reservoirs, since they can better escape predators and competitors. Seasonal ponds, often 0.10-0.15 ha and 1.5-1.8 m deep can be used as rearing ponds for raising advanced fingerlings. Low water levels at the end of the season will make netting and harvesting easy.

Everyone wants advanced fingerlings as early after the rains as possible. They fetch a good price and make marketable fish production possible in seasonal ponds. One way to produce early season advanced fingerlings is to grow them in perennial ponds and store them at high density with minimal feeding for the coming year. Whe such "stunted" fingerlings are stocked into ponds with good feed they grow fast and can be marketed in about 6-8 months.